Methods of manufacturing a light guide test sensor

ABSTRACT

An optic light guide test sensor comprises a light guide, a reagent-coated membrane, and a mesh layer. The reagent-coated membrane and the mesh layer are attached to the light guide at an output end of the light guide. The light guide test sensor is adapted to be used to test the level of an analyte in a biological fluid sample when used with a readhead. A method of manufacturing the light guide test sensor involves providing a plurality of light guides, providing a strip of reagent-coated membrane, and providing a strip of mesh layer. The reagent-coated membrane and mesh layer are attached to the light guides by ultrasonic welding. The reagent-coated membrane and mesh layer may also be attached to the light guides by adhesive.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to application Ser. No. 60/585,309,filed Jul. 2, 2004, which is incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates generally to testing systems fordetermining the concentration of an analyte in a fluid sample, and moreparticularly, to an optical test sensor for use in determining theconcentration of an analyte in a biological fluid.

BACKGROUND OF THE INVENTION

It is often necessary to quickly obtain a sample of blood and perform ananalysis of the blood sample. One example of a need for obtaining asample of blood is in connection with a blood glucose monitoring system,which a user must frequently use to monitor their blood glucose level.

One method of monitoring a person's blood glucose level is with aportable, hand-held blood glucose testing device. The portable nature ofthese devices enables users to conveniently test their blood glucoselevels at a variety of locations. Some of these devices employcalorimetric testing. In a calorimetric assay, a reagent is designed toproduce a colorimetric reaction indicative of a user's blood glucoseconcentration level. An optical instrument incorporated into the testingdevice then reads the calorimetric reaction.

A major drawback associated with optical instruments for readingcalorimetric reactions is contamination of the optical instrument withbiological fluids. Contamination occurs when a biological fluid from aprevious sample contacts the optics and is not removed prior to testingthe next sample. The presence of a biological fluid from a previoussample can reduce the accuracy of the test result of the current sampleby mixing with the current sample or covering a portion of the optics,thus preventing the accurate reading of the current sample. Thus, whatis needed is a device that can isolate the optics from the biologicalfluid sample.

One method of manufacturing current test sensors using traditionalmanufacturing techniques requires the reagent-coated membrane strip andthe mesh layer strip to be cut to the desired size prior to being bondedto a sensor. The small size of the pre-cut reagent-coated membrane andmesh layer makes manufacturing a time consuming, labor intensive, anddifficult task. Thus, it would be desirable to have a method ofmanufacturing a test sensor that is easier to perform.

SUMMARY OF THE INVENTION

According to one embodiment of the present invention an optic lightguide sensor comprises a light guide, a reagent-coated membrane, and amesh layer. The light guide has an input end and an output end. Thereagent-coated membrane is at the output end of the light guide. Thereagent is adapted to react with a fluid sample to indicate the level ofan analyte in the sample. The mesh layer attaches to the membrane.

According to another embodiment, an optic light guide test sensorcomprises a light guide, a mesh layer, and a reagent-coated membrane.The light guide has an input end and an output end. The light guide alsohas protrusions at the output end. A mesh layer attaches to the lightguide protrusions. A gap forms between the output end of the light guideand the mesh layer. The gap is adapted to draw in the sample when usingthe test sensor. A reagent-coated membrane attaches to the mesh layerlocated at the output end of the light guide. The reagent is adapted toreact with a fluid sample to indicate the level of an analyte in thesample.

According to one method of the present invention, the level of ananalyte in a biological fluid is tested. The acts of the method providea light guide test sensor that has a light guide, a reagent-coatedmembrane, and a mesh layer. A readhead that is adapted to operate inconjunction with the light guide test sensor to test the level of ananalyte in a biological fluid is also provided. A person lances an areaof the body to produce a fluid sample. A person collects the sample ofblood with the reagent-coated membrane and the mesh layer of the lightguide test sensor. The person places the light guide test sensor withthe collected sample so that the readhead is in position to test thesample. The method measures the light reflected from the sample.

According to another method of the present invention, a light guide testsensor is manufactured. A plurality of light guides having protrusionsis provided. A strip of reagent-coated membrane is provided. The methodplaces the strip of reagent-coated membrane onto the plurality of lightguides so that the light guide protrusions are in contact with the stripof reagent-coated membrane. Ultrasonic welding melts the protrusions toattach and cut the strip of reagent-coated membrane to the plurality oflight guides. The ultrasonic welding attaches and cuts thereagent-coated membrane at about the same time. The light guide is usedas a die for the attaching and cutting.

According to a further method of the present invention, a light guidetest sensor is manufactured. A plurality of light guides havingprotrusions is provided. A strip of reagent-coated membrane is provided.A strip of mesh layer is provided. The method places the membrane stripand the mesh strip onto the plurality of light guides so that the lightguide protrusions are in contact with the membrane strip, and the meshstrip is in contact with the membrane strip. Ultrasonic welding meltsthe protrusions to attach and cut the strip of reagent-coated membraneand the strip of mesh layer to the plurality of light guides. Theultrasonic welding attaches and cuts the reagent-coated membrane and themesh layer at about the same time. The light guide is used as a die forthe attaching and cutting.

According to yet another method of the present invention, a light guidetest sensor is manufactured. A plurality of light guides are providedthat have an adhesive member attached to one end. A strip ofreagent-coated membrane is also provided. The membrane strip contactsthe plurality of light guides, so that the membrane strip contacts theadhesive members. The membrane strip is cut and attached to theplurality of light guides with a punch as the light guides act as a die.The membrane attaches to the light guide at the adhesive member of thelight guide. The membrane is cut and attached to the light guide atabout the same time.

According to a further embodiment of the present invention, an opticdiffuse light guide sensor comprises an illumination light guide with aninput end and an output end. The sensor also has a detection light guidewith an input end and an output end, where the detector light guideinput end is in close proximity to the illumination light guide outputend. A reagent-coated membrane attaches to the output end of theillumination light guide and the input end of the detection light guide.The membrane is illuminated by light from the output end of theillumination light guide. A mesh layer attaches to the reagent-coatedmembrane and directly contacts the reagent-coated membrane.

According to yet another embodiment of the present invention, an opticreflective-light light guide sensor system comprises a readhead adaptedto determine the amount of analyte in a biological sample. The readheadcomprises a light source to illuminate the sample as well asillumination optics to guide light through the readhead. The readheadalso contains a beam splitter to direct light reflected off the sampleto reflectance optics. The reflectance optics direct reflected light toa detector. The detector generates an output signal indicative of thelight it receives. The output signal is proportional to the amount oflight received. A light guide test sensor collects the a sample to betested. The light guide test sensor comprises a light guide with aninput end and an output end, as well as a reagent-coated membrane and amesh layer that attach to the output end of the light guide.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view of the light guide sensor according to oneembodiment of the present invention;

FIG. 2 is a sectional view of the light guide sensor according toanother embodiment of the present invention;

FIG. 3 is a functional block diagram of the test sensor of FIG. 1 with areadhead according to one embodiment of the present invention;

FIG. 4 is a schematic view of a method of manufacturing a light guidesensor according to one embodiment of the present invention;

FIG. 5 is a schematic view of a method of manufacturing a light guidesensor according to another embodiment of the present invention;

FIG. 6 is a schematic view of a method of manufacturing a light guidesensor according to a further embodiment of the present invention; and

FIG. 7 is a sectional view of the light guide sensor according to afurther embodiment of the present invention.

While the invention is susceptible to various modifications andalternative forms, specific embodiments thereof have been shown by wayof example in the drawings and will herein be described in detail. Itshould be understood, however, that it is not intended to limit theinvention to the particular forms disclosed but, on the contrary, theintention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by theappended claims.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

Referring now to the drawings, and initially to FIG. 1, there is shown alight guide test sensor 10 according to one embodiment of the presentinvention. In one embodiment, the light guide test sensor 10 is usedwith a portable handheld glucose testing device for measuring theglucose concentration in the body fluid (e.g., blood, ISF) of a patient.Specifically, the light guide test sensor 10 of the present invention isused in measuring a colorimetric reaction when a reagent reacts with ananalyte. The light guide test sensor 10 delivers illuminating light andcollects light that reflects off a body fluid sample that reacts on areagent-coated membrane 16 at one end of a light guide 12. Morespecifically, the test sensor 10 is used to measure the degree ofreagent color change resulting from the reaction. The degree of reagentcolor change is indicative of the analyte concentration (e.g, glucose,fructoseamine, etc.) in the body fluid. Colorimetric testing isdescribed in detail in U.S. Pat. No. 6,181,417 B1 (entitled “PhotometricReadhead with Light Shaping Plate”); U.S. Pat. No. 5,518,689 (entitled“Diffuse Light Reflectance Readhead”); and U.S. Pat. No. 5,611,999(entitled “Diffuse Light Reflectance Readhead”); each of which isincorporated herein by reference in its entirety.

According to one embodiment of the present invention, the light guidetest sensor 10 includes a light guide 12, a reagent-coated membrane 16,and a mesh layer 22. The light guide 12 may be molded with an opticallyclear material, such as acrylic. In other embodiments, the light guide12 is molded with other optically clear materials such as, for example,polycarbonate, or polyester.

According to one embodiment, light from a light source is guided throughthe light guide 12 by total internal reflection. The light directedthrough the light guide 12 is intended to be read by a readhead. Thelight guide 12 is able to deliver at its output end 20 a significantamount of the light that is input to the input end 18 of the light guide12 by the light source. According to one embodiment of the presentinvention, the light guide 12 has a square cross-section with dimensionsof about 2.3 mm by about 2.3 mm and a length of about 5 cm. A squarecross section allows mixing of the illuminating and reflecting light soas to minimize the effects of misalignments and manufacturingvariations. The light guide 12 delivers light from the light source tothe reagent-coated membrane 16 at the output end 20 of light guide 12.

In an alternate embodiment of the present invention, the light guide isa waveguide with a transparent core with a higher reflective indexcladding applied. It is further contemplated that the light guide couldbe a hollow waveguide, or be coated with either absorbing or reflectinglayers to enhance the sensor performance.

According to another alternate embodiment of the present invention, thelight guide cross section shape may be any polygon with an even numberof congruent sides.

In yet another alternate embodiment of the present invention the lightguide is tapered, such that the cross sectional area of the light guideat the input end is larger than the cross sectional area of the lightguide at its output end.

The reagent-coated membrane 16 is attached to the light guide 12.According to one embodiment, the reagent-coated membrane 16 contains anenzyme, such as glucose oxidase, capable of catalyzing the oxidationreaction of glucose to gluconic acid and hydrogen peroxide and asubstance having peroxidative activity capable of catalyzing theoxidation of the indicator. The reagent-coated membrane 16 is a porouspolymeric membrane. The membrane 16 may, for example, be made fromnylon, nitrocellulose, acrylic polymers, or combinations thereof. Themembrane 16 acts as a physical matrix to hold the reagent, and themembrane's pores allow the fluid under analysis to quickly wick into themembrane and react with the reagent. The reagent-coated membrane 16 alsoserves as a diffuse reflective background so that a reflectivemeasurement may be made. The dye or indicator in the reagent-coatedmembrane 16 when exposed to blood turns a visually different shade ofcolor, and the shade indicates the glucose level in the blood sample.According to one embodiment of the present invention, a 1 mm diameterlight guide requires less than a seventy (70) nanoliter sample size.Reagent-coated membranes are described in further detail in U.S. Pat.No. 6,190,918, which is herein incorporated by reference in itsentirety.

In a further alternate embodiment of the present invention, fluorescentor phosphorescent assay may be used in the reagent-coated membrane.

The mesh layer 22 is attached to the reagent-coated membrane 16 and actsto control the volume and distribution of the test sample. As shown inFIG. 1, the mesh layer 22 directly contacts the reagent-coated membrane16. The mesh layer 22 quickly spreads the fluid sample over the surfaceof the membrane 16. The fluid sample may move from the mesh layer 22 tothe reagent-coated membrane 16. The mesh layer 22 has pore sizes fromabout 10 microns to about 200 microns. It is further contemplated thatmesh layer 22 may contain a wetting agent to further enhance the samplepick-up and further increase the sample distribution over the membrane16.

According to another embodiment of the present invention depicted inFIG. 2, a light guide test sensor 100 includes a light guide 120, thereagent-coated membrane 16, the mesh layer 22, an input end 180, and anoutput end 200. The light guide 120 is molded with an optically clearmaterial, such as acrylic. In alternate embodiments, the light guide maybe molded with other optically clear materials such as, for example,polycarbonate, or polyester.

Referring still to FIG. 2, the light guide 120 includes protrusions 122.The reagent-coated membrane 16 and the mesh layer 22 are attached to theprotrusions 122 of the light guide 120, such that there is a gap 124between the output end 200 of the light guide 120 and the reagent-coatedmembrane 16 and mesh layer 22. The gap 124 acts as a capillary channelin this embodiment. The capillary channel formed by gap 124 draws thesample into the gap by capillary action. The use of a capillary channelhelps to control the volume of the test sample that the test sensor 100collects. It is desirable to control the sample volume because itimproves the accuracy of the test results.

In a further embodiment of the present invention depicted in FIG. 3, alight guide test sensor 300 includes a separate illumination light guide312 and a detection light guide 322. Light guide sensor 300 furthercomprises the reagent-coated membrane 16 and the mesh layer 22.According to this embodiment, the light present in detection light guide322 is that which reflects off of the reagent-coated membrane 16. Havingan illumination light guide 312 and a detection light guide 322 lowersthe background signal that a readhead detector for reading the lightguide is supplied with by reducing the amount of light in the detectionlight guide 322, thus making the reading more accurate.

Referring now to FIG. 4, the light guide test sensor 10 is shown beingread by a readhead 50. The readhead 50 contains a light source 52 forproducing light, illumination optics 54, a sensor mounting base 56, abeam splitter 58, reflectance optics 60, a detector 62, and electronics(not shown). Meter readheads are described in detail in U.S. Pat. No.5,611,999 (entitled “Diffused Light Reflectance Readhead”), and U.S.Pat. No. 5,518,689 (entitled “Diffused Light Reflectance Readhead”),each of which is incorporated herein by reference in its entirety.

In one embodiment of the present invention, the light source 52 is alight emitting diode (“LED”). The LED mounts on a printed circuit board,which is part of the electronics that control the operations of thereadhead 50. The LED of the light source 52 produces white light. It isfurther contemplated that a plurality of monochromatic light sources mayalso be used. Light from the light source 52 passes through theillumination optics 54 of the readhead 50; the illumination optics 54include an aperture and a lens. A non-limiting example of theillumination optics 54 is a collimation lens that produces asubstantially collimated beam of light. The illumination optics 54directs the light through the beam splitter 58 and a portion of thelight is directed into the light guide test sensor 10. Some of the lightthat arrives at the beam splitter 58 is directed by the beam splitter 58to a reference detector (not shown). The light that is directed into thelight guide sensor 10 reflects off of the test sample that a userapplies to the reagent-coated membrane 16.

To obtain a sample for testing, a user lances an area of the user's skinS, such as the user's fingertip, and a drop of blood 64 is produced atthe lance site. The user then brings the mesh layer 22 and thereagent-coated membrane 16 end of the light guide test sensor 10 intocontact with the blood 64. The blood collects in the reagent-coatedmembrane 16 and in the mesh layer 22, and the blood reacts with thereagent in the reagent-coated membrane 16 to produce a calorimetricreaction. The user then uses light guide test sensor 10 with thereadhead 50 to determine the analyte level present in the sample.

The light that reflects off of the reagent-coated membrane includeslight that reflects within the sample. The light guide test sensor 10collects a portion of the light that reflects within the sample, anddirects this light to the readhead 50.

After collecting the reflected light, the light guide test sensor 10guides the reflected light via the light guide 12 to the readhead 50.The reflected light passes through the beam splitter 58. The beamsplitter 58 directs the reflected light from the light guide sensor 10to the reflectance optics 60, which directs the light onto the detector62. The detector 62 generates an output signal indicative of the lightreceived by the detector. Devices that can be employed as the detector62 include charge coupled devices, photocells, and photodiodes. Thedetector 62 produces an electrical response that is proportional to thereflected light received. The electrical response is interpreted byelectronics (not shown). The electronics convert the analog electricalresponse of the detector 62 into digital data. The electronics alsoinclude a microprocessor (not shown) that stores and utilizes digitaldata to calculate contrast variations indicated by the detector 62 todetermine the analyte level present in the sample.

In an alternate embodiment of the present invention, it is furthercontemplated that the light guide test sensor contains a light trap. Alight trap reduces the specular component of light that reflectsdirectly off of the surface of the reagent-coated membrane. Light thatreflects off of the surface of the reagent-coated membrane may mix withthe light that is reflected off of the sample portion of thereagent-coated membrane causing the reading of the analyte level to beinaccurate. The light trap absorbs this specular component of the light,which increases the accuracy of the test result.

It is also contemplated that the light guide of the light guide testsensor may be optical fibers. According to this alternate embodiment, aplurality of fibers is used as illumination light guides, and a separateplurality of fibers is used as detection light guides. Using a separateplurality of fibers for the detection light guides reduces thebackground signal that the readhead detector is supplied with, thusmaking the reading more accurate.

The light guide test sensor 10 may be manufactured by a method utilizingultrasonic welding. Ultrasonic welding is a process where high frequency(15 kHz-40 kHz) mechanical vibrations are applied to two or more piecesthat are desired to be joined. The vibrations in the material generateheat. This heat causes the materials to melt and form a bond. Pressuremay also be exerted on the pieces while the vibrations are applied toensure a secure bond is formed. According to one embodiment of thepresent invention, as depicted in FIG. 5, a plurality of light guides 12a-c are provided. The light guides 12 a-c include protrusions 140 thatact as pointed energy directors, according to one embodiment. Theprotrusions 140 that act as pointed energy directors are known in theart to act as locations where the ultrasonic energy is concentrated. Astrip of reagent-coated membrane 160 is also provided. The strip ofreagent-coated membrane 160 is brought in contact with the light guides12 a-c. The protrusions 140 contact the reagent-coated membrane strip160 so that the membrane strip on each respective light guide 12 a-c isof the desired size, such as the reagent-coated membrane 16 of FIG. 1.The pieces are then subjected to ultrasonic welding. During theultrasonic welding, the protrusions 140 melt, as they are points ofconcentration of ultrasonic energy. The melted protrusions 140 cause thereagent-coated membrane to form a bond with respective light guides 12a-c. The ultrasonic welding process not only bonds the reagent-coatedmembrane to the light guide, but it also cuts the reagent-coatedmembranes 16 a-c to the desired size, such as reagent-coated membrane 16of FIG. 1.

Once the reagent-coated membrane 16 is bonded with the light guide, themesh layer 22 is attached. According to one embodiment, mesh layer 22 ispre-cut to the desired size and adhesively bonded to the reagent-coatedmembrane 16. Double-sided tape is typically used to form the adhesivebond of the mesh layer 22 to the reagent-coated membrane 16.

In this embodiment, the protrusions 140 are desirable to themanufacturing method as they provide material that will melt to allowthe reagent-coated membrane 160 to bond with light guides 12 a-c. Theprotrusions 140 are also desirable because they allow the opticalproperties of light guides 12 a-c to be minimally affected by the sonicwelding process. If the entire output end 20 of the light guide 12 ofFIG. 1 were allowed to melt and bond the reagent-coated membrane 16 tothe light guide 12, the optical characteristics of the light guide 12could be adversely affected, and the sensor would not function asaccurately.

The use of protrusions 140 allows the light guide 12 to be produced byeither a molding or forming process.

Light guide test sensor 10 may be manufactured by a similar methodutilizing only ultrasonic welding. Referring to FIG. 6, a plurality oflight guides 12 a-c is provided. The light guides 12 a-c includeprotrusions 140 that act as pointed energy directors. A strip of thereagent-coated membrane 160 is provided. A strip of the mesh layer 220is also provided. The strip of reagent-coated membrane 160 and the stripof mesh 220 are brought in contact with the light guides 12 a-c. Theprotrusions 140 contact the reagent-coated membrane strip 160, so thatthe membrane strip on each respective light guide 12 a-c is of thedesired size, such as reagent-coated membrane 16 of FIG. 1. The portionof mesh strip 220 between the protrusions 140 of light guides 12 a-c isalso the desired size, such as mesh layer 22 of FIG. 1. The pieces arethen subjected to ultrasonic welding. During the ultrasonic welding theprotrusions 140 that act as pointed energy directors, the reagent-coatedmembrane strip 160, and the mesh layer strip 220 melt. The melting bondsthe reagent-coated membrane and the mesh layer to respective lightguides 12 a-c. This ultrasonic welding manufacturing method issignificantly more efficient than traditional methods of manufacturing,as it allows much larger strips of reagent-coated membrane and meshlayer to be cut to the desired size and bonded to the light guides bythe ultrasonic welding.

Light guide test sensor 10 may be manufactured by another process usingan adhesive to bond the reagent-coated membrane 16 to the light guide12. According to this embodiment, as depicted in FIG. 7, a plurality oflight guides 12 a-c is provided. A strip of reagent-coated membrane 160is also provided. An adhesive has been applied to the end of the lightguides where the reagent membranes will be attached. An example of anadhesive that might be used in this embodiment is a transparent doublesided tape. The strip of reagent-coated membrane 160 contacts lightguides 12 a-c. A punch 300 contacts the strip of reagent-coated membrane160 and light guides 12 a-c. The punch uses the light guides 12 a-c as adie to cut the strip of reagent-coated membrane 160 to the desired size16 a-c, such as that of reagent-coated membrane 16 of FIG. 1. The punchalso applies pressure to the strip of reagent membrane 160 and lightguides 12 a-c so that once the reagent-coated membrane strip is cut thereagent-coated membrane pieces 16 a-c that are in contact with lightguide 12 a-c bond to the light guides from the adhesive that had beenpreviously applied to light guides 12 a-c.

In addition to the embodiments described above, several embodiments ofthe present invention will now be described.

Alternative Embodiment A

A. An optic light guide test sensor comprising:

a light guide having an input end and an output end;

a reagent-coated membrane, the membrane being located at the output endof the light guide and being attached to the light guide, the reagentbeing adapted to react with a fluid sample to indicate the level of ananalyte in the sample; and

a mesh layer being attached to the membrane.

Alternative Embodiment B

B. An optic light guide test sensor comprising:

a light guide having an input end and an output end, the light guidefurther comprising protrusions located at the output end;

a mesh layer being attached to the light guide protrusions, the lightguide protrusions forming a gap between the output end and the meshlayer, the gap being adapted to draw in the sample when the sensor isbeing used; and

a reagent-coated membrane, the membrane being attached to the mesh layerlocated at the output end of the light guide, the reagent being adaptedto react with a fluid sample to indicate the level of an analyte in thesample.

Alternative Embodiment C

C. A method of testing the level of an analyte in a biological fluid,the method comprising the acts of:

providing a light guide test sensor, the light guide sensor having alight guide, a reagent-coated membrane, and a mesh layer;

providing a readhead that is adapted to operate in conjunction with thelight guide test sensor to test the level of an analyte in thebiological fluid;

lancing an area of the body to produce a sample of the biological fluid;

collecting the sample with the reagent-coated membrane and mesh layer ofthe light guide test sensor;

contacting the light guide test sensor with the collected sample so thatthe readhead is in position to test the sample; and

measuring the light reflected from the sample.

Alternative Embodiment D

D. The method of alternative embodiment C, wherein the analyte isglucose.

Alternative Embodiment E

E. A method of manufacturing a light guide test sensor, the methodcomprising the acts of:

providing a plurality of light guides having a first end and a secondend, the light guides having protrusions at the first end;

providing a strip of reagent-coated membrane;

placing the membrane strip onto the plurality of light guides so thatthe light guide protrusions at the first end thereof are in contact withthe membrane strip; and

attaching and cutting the membrane strip to the plurality of lightguides using ultrasonic welding to melt the protrusions and bond themembrane strip to the plurality of light guides, wherein the attachingand cutting take place at about the same time, and wherein the lightguide is used as a die for the attaching and cutting.

Alternative Embodiment F

F. A method of manufacturing a light guide test sensor, the methodcomprising the acts of:

providing a plurality of light guides having a first end and a secondend, the light guides having protrusions at the first end;

providing a strip of reagent-coated membrane;

providing a strip of mesh layer;

placing the membrane strip and the mesh strip onto the plurality oflight guides so that the light guide protrusions at the first endthereof are in contact with the membrane strip, and the membrane stripis in direct contact with the mesh strip; and

attaching and cutting the membrane strip and the mesh strip to theplurality of light guides using ultrasonic welding to melt theprotrusions and bond the membrane strip and the mesh strip to theplurality of light guides, wherein the attaching and cutting take placeat about the same time, and wherein the light guide is used as a die forthe attaching and cutting.

Alternative Embodiment G

G. A method of manufacturing a light guide test sensor, the methodcomprising the acts of:

providing a plurality of light guides having an adhesive member attachedto one end;

providing a strip of reagent-coated membrane;

contacting the membrane strip to the plurality of light guides so thatthe light guide adhesive members contact the membrane strip; and

attaching and cutting the membrane strip to the plurality of lightguides using a punch to cut the membrane strip using the light guides asa die, wherein the membrane is attached to the light guide by theadhesive member, and wherein the cutting and attaching take place atabout the same time.

Alternative Embodiment H

H. The method of alternative embodiment G, wherein the adhesive membersare double-sided tape.

Alterative Embodiment I

I. A light guide test sensor comprising:

an illumination light guide having an input end and an output end;

a detection light guide having an input end and an output end, thedetector light guide input end being in close proximity to theillumination light guide output end;

a reagent-coated membrane, the membrane located at the output end of theillumination light guide and the input end of the detector light guide,the membrane being attached to the illumination light guide and thedetector light guide, the membrane being illuminated by a light from theoutput end of the illumination light guide; and

a mesh layer being attached and in direct contact with the membrane.

Alternative Embodiment J

J. The light guide test sensor of alternative embodiment I furthercomprising a light trap.

Alternative Embodiment K

K. The light guide test sensor of alternative embodiment J, wherein thelight trap absorbs a specular component of the light from the output endof the illumination light guide.

Alternative Embodiment L

L. The light guide test sensor of alternative embodiment I, wherein theillumination light guide cross section shape is a polygon with an evennumber of congruent sides, and the detection light guide cross sectionshape is a polygon with an even number of congruent sides.

Alternative Embodiment M

M. The light guide test sensor of alternative embodiment L, wherein theillumination light guide cross section shape is square, and thedetection light guide cross section shape is square.

Alternative Embodiment N

N. An optic reflective-light light guide sensor system comprising:

a readhead adapted to determine the amount of an analyte in a biologicalsample, the readhead comprising a light source to provide illuminationto a sample to be tested, illumination optics to guide the lightproduced by the light source through the readhead, a beam splitteradapted to direct light reflected off of the sample to reflectanceoptics, the reflectance optics being adapted to direct reflected lightto a detector, the detector being adapted to generate an output signalindicative of the light received by the detector, the output signalbeing proportional to the amount reflected light received; and a lightguide test sensor adapted to collect a sample, the light guide testsensor comprising a light guide with an input end and an output end, areagent-coated membrane at the output end of the light guide, and a meshlayer attached to the membrane.

While the present invention has been described with reference to one ormore particular embodiments, those skilled in the art will recognizethat many changes may be made thereto without departing from the spiritand scope of the present invention. Each of these embodiments, andobvious variations thereof, is contemplated as falling within the spiritand scope of the invention as defined in the appended claims.

1. A method of manufacturing a light guide test sensor, the methodcomprising the acts of: providing a plurality of light guides having arespective adhesive member attached to one end, each of the plurality oflight guides configured to guide and deliver illuminating light to afluid sample, and guide and deliver reflected light from the fluidsample, each of the plurality of light guides having structure tocontain light being delivered to and from the fluid sample; providing astrip of reagent-coated membrane, the reagent being adapted to reactwith a fluid sample to indicate information relating to an analyte in asample; contacting the membrane strip to the plurality of light guidesby the adhesive member; and attaching and cutting the membrane strip tothe plurality of light guides using a punch to cut the membrane stripand using the light guides as a die, wherein the membrane strip isattached to the plurality of light guides by the adhesive member.
 2. Themethod of claim 1, wherein the adhesive member is double-sided tape. 3.The method of claim 1 further included providing a strip of mesh layerand attaching the mesh layer strip to the membrane strip.
 4. The methodof claim 3 wherein the mesh layer strip is attached to the membranestrip using an adhesive.
 5. The method of claim 1 wherein the cuttingand attaching take place at about the same time.
 6. The method of claim1 wherein the membrane strip is a porous polymeric membrane.
 7. Themethod of claim 1 wherein the light guide is a waveguide with atransparent core with a reflective index cladding applied thereto. 8.The method of claim 1 wherein the light guide is a hollow waveguide withabsorbing layers.
 9. The method of claim 1 wherein the light guide is ahollow waveguide with reflecting layers.
 10. The method of claim 1wherein the light guide includes optical fibers.
 11. The method of claim1 wherein the membrane strip includes a fluorescent assay.
 12. Themethod of claim 1 wherein the membrane strip includes a phosphorescentassay.
 13. The method of claim 1 wherein the light guide furtherincludes a light trap.
 14. A method of manufacturing a light guide testsensor, the method comprising the acts of: providing a plurality oflight guides having a respective adhesive member attached to one end,each of the light guides being a waveguide or a plurality of opticalfibers; providing a strip of reagent-coated membrane, the reagent beingadapted to react with a fluid sample to indicate information relating toan analyte in a sample; contacting the membrane strip to the pluralityof light guides by the adhesive member; and attaching and cutting themembrane strip to the plurality of light guides using a punch to cut themembrane strip and using the light guides as a die, wherein the membranestrip is attached to the plurality of light guides by the adhesivemember.
 15. The method of claim 14, wherein the adhesive member isdouble-sided tape.
 16. The method of claim 14 further included providinga strip of mesh layer and attaching the mesh layer strip to the membranestrip.
 17. The method of claim 14 wherein the cutting and attaching takeplace at about the same time.
 18. The method of claim 14 wherein thelight guide is a waveguide with a transparent core with a reflectiveindex cladding applied thereto.
 19. The method of claim 14 wherein thelight guide is a hollow waveguide with absorbing layers.
 20. The methodof claim 14 wherein the light guide is a hollow waveguide withreflecting layers.
 21. The method of claim 14 wherein the light guideincludes optical fibers.
 22. The method of claim 14 wherein the membranestrip includes a fluorescent assay.
 23. The method of claim 14 whereinthe membrane strip includes a phosphorescent assay.
 24. The method ofclaim 14 wherein the light guide further includes a light trap.
 25. Amethod of manufacturing a light guide test sensor, the method comprisingthe acts of: providing a plurality of light guides having a respectiveadhesive member attached to one end, each of the light guides includinga structure in which light is guided by total internal reflection;providing a strip of reagent-coated membrane, the reagent being adaptedto react with a fluid sample to indicate information relating to ananalyte in a sample; contacting the membrane strip to the plurality oflight guides by the adhesive member; and attaching and cutting themembrane strip to the plurality of light guides using a punch to cut themembrane strip and using the light guides as a die, wherein the membranestrip is attached to the plurality of light guides by the adhesivemember.